The city is trying to figure out how long the traffic light should stay yellow a

ID: 2280533 • Letter: T

Question

The city is trying to figure out how long the traffic light should stay yellow at an intersection. The speed limit on the road is

45.0 km/h and the intersection is 23.0 m wide. A car is traveling at the speed limit in the positive direction and can brake with

an acceleration of 5.20 m/s2. (a) If the car is to stop on the white line, before entering the intersection, what is the minimum

distance from the line at which the driver must apply the brakes? (b) How long should the traffic light stay yellow so that if the

car is just closer than that minimum distance when the light turns yellow, it can safely cross the intersection without having to

speed up?

(a) m

(b) s

a. 45 km/h = 12.5 m/s

v

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